Secrecy Capacity Analysis of FDA Relaying Swipt System with Power Splitting Protocol

In this paper, we study the secrecy capacity for frequency diverse array relaying and simultaneous wireless information and power transfer jointed communication system under the power splitting protocol. The decode-and-forward strategy and direction modulation technique are jointly utilized for relaying to forward signals. We derive closed-form expressions for the ergodic secrecy capacity of the system. Moreover, the impacts of frequency diverse array parameters on the system security performances are also analyzed. The numerical results show that the system security performance under power splitting protocol outperforms time splitting protocol. Meanwhile, the frequency diverse array relaying achieves better security performance than traditional phased-array relaying.